1. Technical Field of the Invention
This invention relates to a system to detect a traffic accident involving crash by monitoring an object to be collided with (for example, an obstacle existing in a direction to which a motorcycle moves) existing in direction to which an object such as a motorcycle going to collide moves, and also relates to a safety device against crashes for a motorcycle which uses a system to protect a rider of the motorcycle from shock of the crash.
2. Prior Art
Currently, as cars are popularized, traffic accidents become one of great social problems. Among traffic accidents, especially traffic accidents involving crashes of motorcycles in which riders are directly knocked down on the roads cause a high death rate and a serious problem.
Lately, to decrease the death rate of traffic accidents involving the crash of motorcycles, various studies or experiments have been conducted. Through such a crash experiment in which this inventor has participated, the rider's condition just after the crash of the motorcycle with a car has been observed at points in time P, Q, R, S, T and U (ref. FIG. 13), and such tests have clarified that the rider suffers the first shock in the first 50 millisecond (at point Q in FIG. 13) after impact. Here, this crash experiment was conducted according to the experiment definition of ISO13232-2.
On the other hand, to decrease the death rate of traffic accidents involving the crash of motorcycles, safety devices against crashes for a motorcycle to protect a rider of the motorcycle from the shock of a traffic accident involving a crash have been proposed. Known safety devices against the crash for a motorcycle, for example, are such as that composed of an air jacket to be worn by a rider, a gas cartridge filled with gas to be injected to the air jacket, and an inflater to get the gas out of the gas cartridge at the crash. According to that type of safety device against a crash for a motorcycle, the inflater is equipped with a starter pin, and as the starter pin is pulled off, the cartridge is opened with a hole whereby gas flows out to the air jacket. Further, the inflater and the gas cartridge are put on the air jacket as one body, the starter pin is put on the motorcycle, and in the traffic accident involving a crash, at the moment when the rider is thrown off from the motorcycle the inflater works so that the air jacket expands.
However, according to the above-described prior safety device against the crash for a motorcycle, there is a problem that the time required for the air jacket to expand after the inflater starts to work is much longer than the time from the moment of impact when the rider suffers the first shock. In FIG. 12, the condition of the air jacket of the prior safety device against a crash for a motorcycle is shown as time passes from the moment when the inflater starts to work. As shown in FIG. 12, the air jacket of the prior safety device against a crash requires about 200 milliseconds from the moment it starts working to get enough inner pressure (about 20 kilopascal) to absorb the shock. But, in 100 milliseconds just after the moment of impact, the rider has already suffered a shock on the chest or head, and further, it is generally believed this shock is very dangerous because of high possibility of a fatal wound. Therefore, to decrease the death rate in an accident, in early stage of a traffic accident involving a crash, preferably before the crash occurs, action against the crash has to be taken.
Accordingly, the present invention aims to provide a system to monitor the course of an object going to collide which enables the system to take an action against the crash by perceiving the crash before it occurs in an early stage of a traffic accident involving the crash, and to provide a safety device against the crash of a motorcycle using the system.